Bacterial cultures have wide industrial uses; including environmental and agricultural uses as bioremediation reagents, as alternatives to harmful chemicals such as certain pesticides, and as agents for improving plant and animal health. Industrial users of bacterial cultures include manufacturers of probiotics and prebiotics, bacterial seed coatings, and soil augmentation product manufacturers.
Particular species of the gram positive bacteria Bacillus have found uses in agriculture as antifungal agents. For example, U.S. Pat. No. 6,589,524 refers to the use of B. cereus, B. amyloliquefaciens, and B. subtilis for biological control of pathogenic fungi. U.S. Pat. No. 6,830,459 refers to application of Bacillus, including B. subtilis in combination with chitosanase inducers for preventing or treating microbial colonization and fungal growth. U.S. Pat. No. 6,423,310 refers to use of biological coatings that confer protective and curative effects for the control of postharvest decay. The coatings have antifungal properties and include chitosan salts, antagonistic organisms including yeast or bacteria such as B. subtilis, and a cation. Other uses of Bacillus have included uses of Bacillus preparations for soil conditioning, for enhancing fermentation of cellulosic materials, and as a deodorant for feces and urine of animals; as referred to in U.S. Pat. No. 5,733,355. U.S. Pat. No. 5,919,695 refers to an atypical B. subtilis strain for use in controlling molds and other spoilage flora in various materials, particularly foods.
Sporulation in gram positive bacteria, including Bacillus, leads to formation of spores (endospores) which are dormant; and therefore desirable for industrial purposes including manufacturing, shipping, and storage. Activation of the dormant spores leads to germination and growth of active bacteria. Sporulation in B. subtilis has been classically viewed as a unicellular differentiation that occurs in response to nutritional starvation. More recently, in addition to complex morphological and metabolic changes, changes in the soluble protein profile of the bacterium, including identification of specific proteins associated with sporulation have been reported. For example, the extracellular differentiation factor A (EDF-A), a secreted factor, is reported to be required, in addition to starvation conditions, for efficient sporulation in B. subtilis. See Waites W M, and Wild D G (1970), J. General Microbiology, 61: 311-317; Grossman A D, and Losick R (1988) Proc. Natl. Acad. Sci. USA, 85: 4369-4373; Driks A (2002) Cellular and Mol. Life Sciences 59: 389-391.